OMAP: DMA: Introduce errata handling feature
Implement errata handling to use flags instead of cpu_is_* and
cpu_class_* in the code.
The errata flags are initialized at init time and during runtime we are
using the errata variable (via the IS_DMA_ERRATA macro) to execute the
required errata workaround.
Reused errata handling patch from: Peter Ujfalusi
<peter.ujfalusi@nokia.com>
https://patchwork.kernel.org/patch/231191/
Changes to above patch:
1. Changes are done for converting all the existing errata work arounds
to use this feature.
2. Detailed description for each errata is added.
3. Fixed bug in SET_DMA_ERRATA macro
4. Bit shifting in macro definitions are replaced with BIT() macro
Signed-off-by: G, Manjunath Kondaiah <manjugk@ti.com>
Tested-by: Kevin Hilman <khilman@deeprootsystems.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index 49a7cd4..6f51bf3 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -144,6 +144,7 @@
#define OMAP_FUNC_MUX_ARM_BASE (0xfffe1000 + 0xec)
static int enable_1510_mode;
+static u32 errata;
static struct omap_dma_global_context_registers {
u32 dma_irqenable_l0;
@@ -1088,31 +1089,17 @@
cur_lch = next_lch;
} while (next_lch != -1);
- } else if (cpu_is_omap242x() ||
- (cpu_is_omap243x() && omap_type() <= OMAP2430_REV_ES1_0)) {
-
- /* Errata: Need to write lch even if not using chaining */
+ } else if (IS_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS))
dma_write(lch, CLNK_CTRL, lch);
- }
omap_enable_channel_irq(lch);
l = dma_read(CCR, lch);
- /*
- * Errata: Inter Frame DMA buffering issue (All OMAP2420 and
- * OMAP2430ES1.0): DMA will wrongly buffer elements if packing and
- * bursting is enabled. This might result in data gets stalled in
- * FIFO at the end of the block.
- * Workaround: DMA channels must have BUFFERING_DISABLED bit set to
- * guarantee no data will stay in the DMA FIFO in case inter frame
- * buffering occurs.
- */
- if (cpu_is_omap2420() ||
- (cpu_is_omap2430() && (omap_type() == OMAP2430_REV_ES1_0)))
- l |= OMAP_DMA_CCR_BUFFERING_DISABLE;
-
+ if (IS_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING))
+ l |= OMAP_DMA_CCR_BUFFERING_DISABLE;
l |= OMAP_DMA_CCR_EN;
+
dma_write(l, CCR, lch);
dma_chan[lch].flags |= OMAP_DMA_ACTIVE;
@@ -1128,8 +1115,8 @@
dma_write(0, CICR, lch);
l = dma_read(CCR, lch);
- /* OMAP3 Errata i541: sDMA FIFO draining does not finish */
- if (cpu_is_omap34xx() && (l & OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) {
+ if (IS_DMA_ERRATA(DMA_ERRATA_i541) &&
+ (l & OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) {
int i = 0;
u32 sys_cf;
@@ -1229,11 +1216,7 @@
else
offset = dma_read(CSAC, lch);
- /*
- * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
- * read before the DMA controller finished disabling the channel.
- */
- if (!cpu_is_omap15xx() && offset == 0)
+ if (IS_DMA_ERRATA(DMA_ERRATA_3_3) && offset == 0)
offset = dma_read(CSAC, lch);
if (cpu_class_is_omap1())
@@ -1814,7 +1797,7 @@
{
int *channels;
u32 l, i;
- u32 sys_cf;
+ u32 sys_cf = 0;
/* Check for input params */
if (unlikely((chain_id < 0 || chain_id >= dma_lch_count))) {
@@ -1829,15 +1812,13 @@
}
channels = dma_linked_lch[chain_id].linked_dmach_q;
- /*
- * DMA Errata:
- * Special programming model needed to disable DMA before end of block
- */
- sys_cf = dma_read(OCP_SYSCONFIG, 0);
- l = sys_cf;
- /* Middle mode reg set no Standby */
- l &= ~((1 << 12)|(1 << 13));
- dma_write(l, OCP_SYSCONFIG, 0);
+ if (IS_DMA_ERRATA(DMA_ERRATA_i88)) {
+ sys_cf = dma_read(OCP_SYSCONFIG, 0);
+ l = sys_cf;
+ /* Middle mode reg set no Standby */
+ l &= ~((1 << 12)|(1 << 13));
+ dma_write(l, OCP_SYSCONFIG, 0);
+ }
for (i = 0; i < dma_linked_lch[chain_id].no_of_lchs_linked; i++) {
@@ -1856,8 +1837,8 @@
/* Reset the Queue pointers */
OMAP_DMA_CHAIN_QINIT(chain_id);
- /* Errata - put in the old value */
- dma_write(sys_cf, OCP_SYSCONFIG, 0);
+ if (IS_DMA_ERRATA(DMA_ERRATA_i88))
+ dma_write(sys_cf, OCP_SYSCONFIG, 0);
return 0;
}
@@ -2063,12 +2044,7 @@
if (unlikely(status & OMAP2_DMA_TRANS_ERR_IRQ)) {
printk(KERN_INFO "DMA transaction error with device %d\n",
dma_chan[ch].dev_id);
- if (cpu_class_is_omap2()) {
- /*
- * Errata: sDMA Channel is not disabled
- * after a transaction error. So we explicitely
- * disable the channel
- */
+ if (IS_DMA_ERRATA(DMA_ERRATA_i378)) {
u32 ccr;
ccr = dma_read(CCR, ch);
@@ -2168,13 +2144,7 @@
dma_write(omap_dma_global_context.dma_irqenable_l0,
IRQENABLE_L0, 0);
- /*
- * A bug in ROM code leaves IRQ status for channels 0 and 1 uncleared
- * after secure sram context save and restore. Hence we need to
- * manually clear those IRQs to avoid spurious interrupts. This
- * affects only secure devices.
- */
- if (cpu_is_omap34xx() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
+ if (IS_DMA_ERRATA(DMA_ROMCODE_BUG))
dma_write(0x3 , IRQSTATUS_L0, 0);
for (ch = 0; ch < dma_chan_count; ch++)
@@ -2182,6 +2152,87 @@
omap_clear_dma(ch);
}
+static void configure_dma_errata(void)
+{
+
+ /*
+ * Errata applicable for OMAP2430ES1.0 and all omap2420
+ *
+ * I.
+ * Erratum ID: Not Available
+ * Inter Frame DMA buffering issue DMA will wrongly
+ * buffer elements if packing and bursting is enabled. This might
+ * result in data gets stalled in FIFO at the end of the block.
+ * Workaround: DMA channels must have BUFFERING_DISABLED bit set to
+ * guarantee no data will stay in the DMA FIFO in case inter frame
+ * buffering occurs
+ *
+ * II.
+ * Erratum ID: Not Available
+ * DMA may hang when several channels are used in parallel
+ * In the following configuration, DMA channel hanging can occur:
+ * a. Channel i, hardware synchronized, is enabled
+ * b. Another channel (Channel x), software synchronized, is enabled.
+ * c. Channel i is disabled before end of transfer
+ * d. Channel i is reenabled.
+ * e. Steps 1 to 4 are repeated a certain number of times.
+ * f. A third channel (Channel y), software synchronized, is enabled.
+ * Channel x and Channel y may hang immediately after step 'f'.
+ * Workaround:
+ * For any channel used - make sure NextLCH_ID is set to the value j.
+ */
+ if (cpu_is_omap2420() || (cpu_is_omap2430() &&
+ (omap_type() == OMAP2430_REV_ES1_0))) {
+ SET_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING);
+ SET_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS);
+ }
+
+ /*
+ * Erratum ID: i378: OMAP2plus: sDMA Channel is not disabled
+ * after a transaction error.
+ * Workaround: SW should explicitely disable the channel.
+ */
+ if (cpu_class_is_omap2())
+ SET_DMA_ERRATA(DMA_ERRATA_i378);
+
+ /*
+ * Erratum ID: i541: sDMA FIFO draining does not finish
+ * If sDMA channel is disabled on the fly, sDMA enters standby even
+ * through FIFO Drain is still in progress
+ * Workaround: Put sDMA in NoStandby more before a logical channel is
+ * disabled, then put it back to SmartStandby right after the channel
+ * finishes FIFO draining.
+ */
+ if (cpu_is_omap34xx())
+ SET_DMA_ERRATA(DMA_ERRATA_i541);
+
+ /*
+ * Erratum ID: i88 : Special programming model needed to disable DMA
+ * before end of block.
+ * Workaround: software must ensure that the DMA is configured in No
+ * Standby mode(DMAx_OCP_SYSCONFIG.MIDLEMODE = "01")
+ */
+ if (cpu_is_omap34xx() && (omap_type() == OMAP3430_REV_ES1_0))
+ SET_DMA_ERRATA(DMA_ERRATA_i88);
+
+ /*
+ * Erratum 3.2/3.3: sometimes 0 is returned if CSAC/CDAC is
+ * read before the DMA controller finished disabling the channel.
+ */
+ if (!cpu_is_omap15xx())
+ SET_DMA_ERRATA(DMA_ERRATA_3_3);
+
+ /*
+ * Erratum ID: Not Available
+ * A bug in ROM code leaves IRQ status for channels 0 and 1 uncleared
+ * after secure sram context save and restore.
+ * Work around: Hence we need to manually clear those IRQs to avoid
+ * spurious interrupts. This affects only secure devices.
+ */
+ if (cpu_is_omap34xx() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
+ SET_DMA_ERRATA(DMA_ROMCODE_BUG);
+}
+
/*----------------------------------------------------------------------------*/
static int __init omap_init_dma(void)
@@ -2342,6 +2393,7 @@
dma_chan[1].dev_id = 1;
}
}
+ configure_dma_errata();
return 0;
diff --git a/arch/arm/plat-omap/include/plat/dma.h b/arch/arm/plat-omap/include/plat/dma.h
index dfb1b10..2378399 100644
--- a/arch/arm/plat-omap/include/plat/dma.h
+++ b/arch/arm/plat-omap/include/plat/dma.h
@@ -283,6 +283,18 @@
#define DMA_CH_PRIO_HIGH 0x1
#define DMA_CH_PRIO_LOW 0x0 /* Def */
+/* Errata handling */
+#define IS_DMA_ERRATA(id) (errata & (id))
+#define SET_DMA_ERRATA(id) (errata |= (id))
+
+#define DMA_ERRATA_IFRAME_BUFFERING BIT(0x0)
+#define DMA_ERRATA_PARALLEL_CHANNELS BIT(0x1)
+#define DMA_ERRATA_i378 BIT(0x2)
+#define DMA_ERRATA_i541 BIT(0x3)
+#define DMA_ERRATA_i88 BIT(0x4)
+#define DMA_ERRATA_3_3 BIT(0x5)
+#define DMA_ROMCODE_BUG BIT(0x6)
+
enum omap_reg_offsets {
GCR, GSCR, GRST1, HW_ID,